Key trait: For all of Napier's brilliance -- and he has been brilliant -- the Huskies are where they are because of sound defensive principles and great perimeter shooting. The latter is almost as important as the former: If Ryan Boatright, DeAndre Daniels and Niels Giffey weren't so potent from the perimeter, UConn's offense would be easy to stop. They are, and it's not.
Tennessee vs. Michigan (Friday, 7:15 p.m. ET); Kentucky vs. Louisville (Friday, 9:45 p.m. ET)
How they got here: If you're reading this column, you almost certainly watched Sunday's masterpiece of a third-round game between Kentucky and unbeaten No. 1 seed Wichita State. And you may be asking yourself: How in the name of Captain Planet did that team in blue get seeded eighth? Your point is well taken. Truth is, it wasn't all that long ago that Kentucky's group of massively hyped freshmen was quite literally shrugging its way through the SEC schedule. They just about drove John Calipari mad in the process. Only in the past few weeks have Aaron and Andrew Harrison begun to play the way Calipari had hoped, devastating opposing defenses with physical drives to the lane, working Calipari's simple-but-effective dribble-drive sets ... and thus only recently has Kentucky begun to resemble the team everyone expected in October. Now that the Wildcats do, duck.
Key trait: All season, even in its worst outings, Kentucky's floor has been impressively maintained by one facet of its game: interior offensive strength. To be more specific, star freshman forward Julius Randle has bulled his way through opposing defenses all season, tearing down offensive rebounds and earning constant trips to the line. UK has never had to shoot the ball all that well, because Randle has made the Wildcats the second-best offensive rebounding team in the country, and earned 268 free throw attempts in doing so. Put simply? He's a beast.
How they got here: The Cardinals' seed was the most oft-cited complaint directed at the selection committee this season, but folks shouldn't have been so surprised. Yes, Louisville played the best basketball down the stretch of the season, and yes, advanced analytics tell us Rick Pitino's team is one of the best two or three teams in the country. But because the Cardinals' nonconference schedule was weak, and its own league suffered from bottom-half drag, the committee saw a résumé that belied just how devastatingly good Russ Smith and the defending national champions had been for months. Oh well: Nearly 10 percent of the 11 million ESPN Tournament Challenge brackets picked the Cardinals to win the national title anyway.
Key trait: It's hard to pick just one. There is Smith's unmatched ability to create his own shot and find teammates in unforeseeable ways; there is Montrezl Harrell's low-post strength; there is Luke Hancock's calm, timely playmaking, which paid dividends in the Cardinals' first-round scare against Manhattan. But more than anything, Louisville shreds opponents because it presses and harasses out to 30 feet, and sometimes 94. Smith is just as valuable as the lead fixture in a defense that both turns opponents over at a high rate and holds opponents to the fourth-lowest effective field goal percentage in the country -- exactly the style that carried Louisville to a national title last season.